Filler neck cap assembly

ABSTRACT

A cap assembly (4) for a filler neck, especially of a motor vehicle fuel tank, with a somewhat pot-shaped insert (7) insertable to form a seal for the end of the filler neck (1), having projections (6) at its outer periphery engaging in bayonet or threaded grooves (5) in the filler neck and covered at its upper end projecting from the filler neck by a cap (8), and fitted with an over/underpressure valve (11) which acts via apertures (35, 39) in the base of the insert (7) and in its upper end and/or in the cap (8) between the inside of the filler neck and the atmosphere. The entire insert (7) is pressed from sheet steel and the over/underpressure valve (11) is encapsulated in a valve housing (12) fitted in the insert (7) and having a peripheral flange secured by the folded edge (14) of the insert (7).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a filler neck cap assembly, especiallyof an automotive fuel tank, with an approximately pot-shaped insertsealingly insertable into the filler neck end, which insert is providedwith projections for engaging in bayonet or helical slots of the fillerneck, at its upper end protruding from the filler neck end iscircumferentially embraced by a top cap, and contains a pressure vacuumrelief valve, which communicates between the filler neck interior andthe atmosphere via apertures in the bottom of the insert on the one handand in the upper end of the insert and/or in the top cap on the otherhand, the pressure vacuum relief valve being encased in a self-containedvalve housing, which is enclosed in the insert and equipped with acircumferential flange.

2. Background of the Invention

Such a cap assembly is known from U.S. Pat. No. 4,133,346 which shows afiller neck cap assembly with a pressure vacuum relief valve encased ina sheet-metal housing. The sheet-metal housing of the valve ispress-fitted into an insertable plastic closure engaging in the fillerneck end. This design has the disadvantage that a separate plasticinjection-molding process is necessary for manufacture of the insert,and that the pressure vacuum relief valve, once pressed into the insert,can not be replaced without being destroyed. Modular replacement of thevalve to select a specified valve function is not possible.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the invention is to provide a cap assembly which can befabricated and assembled more simply and more inexpensively. This objectis achieved according to the invention by the fact that the insert isformed from sheet metal and the pressure relief has a circumferentialflange which is secured by the rebent rim of the insert.

By assembling the pressure vacuum relief valve by simple rebending ofthe insert made from sheet metal in the manner according to theinvention, prefabrication, stocking of modular components, and simple insitu assembly of cap assemblies with different valve functions orstandardized valve casings with different external cap assembly forms isachieved. The insert is formed inexpensively from sheet metal and isstiffened by the enclosed pressure vacuum relief valve. As a result thedanger of deformation and inadvertent opening of the valve is veryslight.

Preferably the rim of the insert is provided with tongues foldable overinwardly, preferably made from a welded-on ring, for securing thecircumferential flange of the valve housing, thus making it a verysimple matter to fix the valve housing.

According to a further preferred feature of the invention, a collardepending downwardly from the circumference of the bottom of the insertis formed from a fold of the wall material of the insert, and at twoplaces at least distributed over the circumference is forced radiallyoutward to obtain thereat the respective projections by taking advantageof the yielding behavior of the wall material. This integrated type offabrication of the projections represents a decisive cost benefit.

In a particularly favorable embodiment, the rim of the insert isprolonged at the connection to its rebending section securing thecircumferential flange of the valve housing and is outwardly folded overat an obtuse angle, preferably 160°, the top cap being snapped onto thecuff by means of snap-in locking projections. The cuff thus forms asliding surface, which deflects the top cap away from the insert underthe effect of a radial force, thus further increasing crash safety.

In each case, it is advantageous for the insert to be equipped at itsupper end with radial notches for engagement with internals ribs of thetop cap. This represents a simple and effective way of transferring thetorque necessary for operation of the cap assembly from the top cap tothe insert.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail hereinafter by means ofan example illustrated in the attached drawing. The single FIGURE of thedrawing shows the cap assembly according to the invention in combinationwith a filler neck, a section of which is illustrated, the left andright halves of the FIGURE showing axial section halves disposed atright angles to each other.

DETAILED DESCRIPTION

In the FIGURE there is shown the upper end 1 of a filler neck (notfurther illustrated), which leads to an automotive fuel tank. Onto thefiller neck end 1 there is slipped a metal ring 2, an O-ring 3 beinginterposed therebetween. The metal ring 2 is used to anchor a capassembly denoted as a whole by 4 and for this purpose is provided at itsinside circumference with bayonet or helical slots 5 for engagement ofcorresponding projections 6 (to be described in detail hereinafter) ofthe cap assembly 4. Between the cap assembly 4 and the metal ring 2there is provided an annular profiled sealing element 4'. Between themetal ring 2 and the end face of the filler neck end 1 there is defineda guide funnel 2' to guide a fuel nozzle (not illustrated) forrefuelling.

Instead of the use of a metal ring for anchoring the cap assembly 4, thefiller neck end 1 could also be constructed with corresponding bayonetor helical slots 5.

The cap assembly 4 comprises substantially a pot-shaped insert 7 formedfrom sheet metal, which carries the projections 6 and a top cap 8,formed from plastic, pushed onto the upper end of the insert 7protruding from the filler neck end 1. The top cap 8 is equipped with acentral hand grip 9.

The projections 6 are obtained by simple deformation of the wallmaterial of the insert 7. For this purpose, there is formed from a foldof the wall material a collar 10 depending downwardly from thecircumference of the bottom of the insert 7 as well as--by takingadvantage of the yielding behavior of the wall material--a radiallyoutwardly forced projection 6 at each of at least two places distributedover the circumference. In this regard it is immaterial whether theprojections 6 and then the collar 10 are produced by folding over orvice versa or whether both elements are produced in a single deformationstep.

In insert 7 there is contained a pressure vacuum relief valve denoted asa whole by 11. The pressure vacuum relief valve 11 is completelyenclosed in a cylindrical valve housing 12, which is provided at itsupper end with a circumferential flange 13, with which it is secured inthe rebent rim 14 of the insert 7. Rebending of the rim 14 around thecircumferential flange 13 can be achieved, for example, by beading or,as in the illustrated case, by inward bending of tongues 15, which areformed in a welded-on ring 16. Alternatively, the tongues 15 can also beformed integrally with the rest of insert 7.

At the connection to the rebending region securing the circumferentialflange 13, the rim 14 is prolonged and folded back outwardly at anobtuse angle of approximately 160° relative to the axial direction, thusproducing a cuff 17 in the form of a truncated cone, onto which the topcap 8 can be snapped by means of inwardly directed snap-in lockingprojections 18. The oblique outside circumferential face of the cuff 17favors lifting of the top cap 8 from the insert 7 if a radial force isexerted on the top cap 8 in the event of a crash.

The top cap 8 is equipped with radial internal ribs 19, which engage inradial notches 20 in the ring 16 and transmit a torque applied on thetop cap to the insert 7, in order to attach it to or detach it from thefiller neck. Alternatively, the top cap 8 could be equipped with radialnotches and the ring 16 with radial ribs, e.g., for simpler fabricationof the top cap by injection molding.

The valve housing 12 of the pressure vacuum relief valve 11 comprises asubstantially pot-shaped container part 21 of formed sheet metalcombined with a cover part 22 of rigid material, such as a metal platewith a thickness of 3 mm. The circumferential rim of the cover part 22is embraced by the rebent upper rim of the container part 21 and formstogether therewith the circumferential flange 13 of the valve housing12.

A valve spindle 23 is mounted axially movably in the valve housing 12.The valve spindle 23 passes through a central aperture 24 in the coverpart 22 and a central aperture 25 in the bottom of the container part 21and is guided axially by these two apertures.

The valve spindle 23 carries a first valve disk 26 (integrally formedthereon), which cooperates with an annular sealing element 27 in a firstannular region 28. The annular sealing element 27 is secured between thecover part 22 and the container part 21. On the valve spindle 23 thereis also guided axially movably a collar 29, which carries a second valvedisk 30, which cooperates with the annular sealing element 27 in asecond annular region 31.

The first valve disk 26 is biased toward the annular sealing element 27via a compression spring 32, which acts between a shouldered ring 33fixed axially on the valve spindle 23 and the second valve disk 30. Thesecond valve disk 30 is also biased toward the annular sealing element27 by means of a compression spring 34, which is braced against thebottom of the container part 21.

Flow apertures 35 to 39, which are cut out of the insert 7, thecontainer part 21, the second valve disk 30, the annular sealing element27, the cover part 22 and the rim 16, provide either a flow path via thevalve gap between the first valve disk 26 and annular sealing element 27if pressure builds up in the interior of the filler neck 1, or a flowpath via the valve gap between the second valve disk 30 and annularsealing element 27 if vacuum is produced in the interior of the fillerneck 1. The functional principle of such a pressure vacuum relief valveis known in the art.

The invention is obviously not limited to the illustrated embodiment.For example, the pressure vacuum relief valve may have any known designor function and, for example, the valve disks can even fitconcentrically on one side of the annular sealing element. Furthermore,the exact form of the insert 7, its projections 6 and its rim isoptional, provided it can be fabricated merely from inexpensive sheetmetal and stiffened adequately by the enclosed, encased valve.

We claim:
 1. A filler neck cap assembly comprising:an insert sealinglyinsertable into a filler neck of a fuel tank, the insert having anenclosed bottom and sides, and with its top having an opening thereinsurrounded by a rim; a top cap coupled to the top of the insert, the topcap and insert defining a space therebetween; and a self-contained valvehousing enclosing a pressure vacuum relief valve, the self-containedvalve housing being accommodated in said space and having acircumferential flange; said rim being bendable between a first positionin engagement with said circumferential flange to secure saidself-contained valve housing to the insert, and a second position indisengagement from said circumferential flange to release saidself-contained valve housing from said insert for removal thereof fromsaid space.
 2. A filler neck cap assembly according to claim 1 furtherincluding first apertures in the insert and second apertures in at leastone of the insert and the top cap, and wherein the pressure vacuumrelief valve communicates via the first and second apertures with bothan interior of the filler neck and the atmosphere.
 3. A filler neck capassembly according to claim 1, wherein the rim includes tongues whichare inwardly foldable to engage the circumferential flange.
 4. A fillerneck cap assembly according to claim 3 wherein the tongues are made froma welded-on ring.
 5. A filler neck cap assembly according to claim 1,wherein the insert includes a collar extending downwardly from acircumference of the bottom thereof, the collar extending radiallyoutward at least at two places on the circumference of the bottom of theinsert to define projections.
 6. The filler neck cap assembly of claim5, wherein the collar is formed from a fold of material constituting thewalls of said insert.
 7. A filler neck cap assembly according to claim1, wherein the insert includes a rebending region proximate said rim atwhich the rim extends radially outward and is folded over to define acuff, the top cap including snap-in locking projections for attachmentto the cuff.
 8. A filler neck cap assembly according to claim 7, whereinthe rim is outwardly folded over at an angle of 160°.
 9. A filler neckcap assembly according to claim 1, wherein the upper end of the insertincludes radial notches for engagement with internal ribs of the topcap.
 10. A filler neck cap assembly according to claim 1, wherein theinsert is made of sheet metal.
 11. A filler neck cap assembly accordingto claim 1, wherein the self-contained valve housing comprises anopen-ended container made of sheet metal and a disk-shaped cover havinga circumferential edge engaging walls at the open end of the containerso as to form the circumferential flange.
 12. A filler neck cap assemblycomprising:an insert sealingly insertable into a filler neck of a fueltank, the insert having an enclosed bottom and sides, and with its tophaving an opening therein surrounded by a rim; a top cap coupled to thetop of the insert, the top cap and insert defining a space therebetween;and a self-contained valve housing enclosing a pressure vacuum reliefvalve, the self-contained valve housing being accommodated in said spaceand having a circumferential flange; wherein the circumferential flangeis releasably engagable with the rim such that the self-contained valvehousing, once secured to the insert, is releasable and the pressurevacuum relief valve is removable from the valve housing and replaceable,and wherein after replacement of the pressure vacuum relief valve, theself-contained valve housing is re-secured to the insert with thecircumferential flange being releasably engagable with the rim.
 13. Afiller neck cap assembly comprising:an insert sealingly insertable intoa filler neck of a fuel tank, the insert having an enclosed bottom andsides, and with its top having an opening therein surrounded by a rim; atop cap coupled to the top end of the insert, the top cap and insertdefining a space therebetween; and a self-contained valve housing forenclosing a pressure vacuum relief valve, the self-contained valvehousing being accommodated in said space and having a circumferentialflange, the pressure vacuum relief valve including an elongated valvebody mounted to be axially movable within and guided by the valvehousing.
 14. The filler neck cap assembly of claim 13, wherein saidelongated valve body is guided at one end by an opening in a bottom ofsaid valve housing and guided at an opposite end by an opening in a topof said valve housing.
 15. A filler neck cap assembly comprising:aninsert sealingly insertable into a filler neck of a fuel tank, theinsert having an enclosed bottom and sides, and with its top having anopening therein surrounded by a rim; a top cap coupled to the top end ofthe insert, the top cap and insert defining a space therebetween; and aself-contained valve housing for enclosing a pressure vacuum reliefvalve, the self-contained valve housing being accommodated in said spaceand having a circumferential flange, the pressure vacuum relief valvebeing a single valve including a planar surface which is movably mountedproximate an opening in said self-contained housing, the planar surfaceof said pressure vacuum relief valve constituting at least part of avalve closure for said opening, and being movably reactive both to ahigh pressure in an interior of the filler neck relative to theatmosphere and a low pressure in the interior of the filler neckrelative to the atmosphere.
 16. The filler neck cap assembly of claim15, wherein a cross-section of said insert is substantially U-shaped,with said planar surface of the pressure vacuum relief valve having asize substantially corresponding to said opening.